Image relay waveguide and method of producing same
Described are embodiments of a process including patterning one or more reflectors on a surface of a substrate of a material, the surface oriented at a selected angle relative to a (100) crystallographic plane of the material, and etching one or more reflectors in the surface, each reflector including one or more reflective surfaces formed by (111) crystallographic planes of the material. Also described are process embodiments for forming a molded waveguide including preparing a waveguide mold, the waveguide mold comprising a master mold including one or more reflectors on a surface of a substrate of a master mold material, the surface oriented at a selected angle relative to a (100) crystallographic plane of the material, each reflector including one or more reflective surfaces formed by (111) crystallographic planes of the material, injecting a waveguide material into the waveguide mold, and releasing the molded waveguide from the waveguide mold.
Latest Google Patents:
- Thermal Mitigation for An Electronic Speaker Device and Associated Apparatuses and Methods
- NETWORK ADDRESS TRANSLATION FOR VIRTUAL MACHINES
- LINK MARGIN IMPROVEMENTS USING A VARIABLE PHYSICAL LAYER SYMBOL RATE
- Multi-Output Decoders for Multi-Task Learning of ASR and Auxiliary Tasks
- BROWSING HIERARCHICAL DATASETS
The disclosed embodiments relate generally to optics and in particular, but not exclusively, to an image relay waveguide and methods of making the same.
BACKGROUNDWaveguides are used to channel electromagnetic radiation and transport it from an origin to a destination. Typically, radiation such as visible light enters one part of the waveguide, is transported through the waveguide by reflection from the sides of the waveguide, and exits at another part of the waveguide. In certain applications waveguides must be carefully manufactured to very tight dimensional and angular tolerances so that the information content of the radiation traveling through the waveguide is preserved.
Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.
Embodiments of an image relay waveguide and a method for making the same are described. Numerous specific details are described to provide a thorough understanding of embodiments of the invention, but one skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In some instances, well-known structures, materials, or operations are not shown or described in detail but are nonetheless encompassed within the scope of the invention.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one described embodiment. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in this specification do not necessarily all refer to the same embodiment. Furthermore, the particular features, structures, or characteristics described can be combined in any suitable manner in one or more embodiments.
In one embodiment, reflective surfaces 616a-616c with angles of approximately 19.3 degrees can be formed using the process embodiments previously disclosed, making the angle between rays 614 and the reflective surfaces approximately 38.6 degrees. The critical angle for total internal reflection is given by:
where n1 is the index of refraction of the medium in which the waveguide is placed and n2 is the index of refraction of waveguide material 602. This means that in an embodiment where reflective surfaces of the waveguide interface with air (i.e., n1=1) waveguide's index of refraction n2 must be greater than 1.6. High-index monomers used in modern spectacle lenses meet this requirement. For materials with lower index of refraction, such as common glasses, the surfaces can be coated with metal or a multilayer film stack to provide high reflectance to the propagating rays.
The above description of illustrated embodiments of the invention, including what is described in the abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. These modifications can be made to the invention in light of the above detailed description.
The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.
Claims
1. A process for forming a molded waveguide, the process comprising:
- preparing a waveguide mold, the waveguide mold comprising a master mold including one or more reflectors on a surface of a substrate of a master mold material, the surface oriented at a selected angle relative to a (100) crystallographic plane of the material, each reflector including one or more reflective surfaces formed by (111) crystallographic planes of the material;
- coating the surface of the master mold with a layer that prevents the waveguide material from sticking to the mold;
- injecting a waveguide material into the waveguide mold; and
- releasing the molded waveguide from the waveguide mold.
2. The process of claim 1, further comprising curing the waveguide material.
3. The process of claim 1 wherein the master mold material is single crystal silicon.
4. The process of claim 1 wherein the selected angle is approximately half the angle between (111) crystallographic planes of the material.
5. The process of claim 1 wherein the coating is metal, silicon oxide, aluminum oxide or Teflon.
4711512 | December 8, 1987 | Upatnieks |
5076664 | December 31, 1991 | Migozzi |
5093567 | March 3, 1992 | Staveley |
5539422 | July 23, 1996 | Heacock et al. |
5696521 | December 9, 1997 | Robinson et al. |
5715337 | February 3, 1998 | Spitzer et al. |
5771124 | June 23, 1998 | Kintz et al. |
5815126 | September 29, 1998 | Fan et al. |
5844530 | December 1, 1998 | Tosaki |
5886822 | March 23, 1999 | Spitzer |
5896232 | April 20, 1999 | Budd et al. |
5943171 | August 24, 1999 | Budd et al. |
5949583 | September 7, 1999 | Rallison et al. |
6023372 | February 8, 2000 | Spitzer et al. |
6091546 | July 18, 2000 | Spitzer |
6115521 | September 5, 2000 | Tran et al. |
6172657 | January 9, 2001 | Kamakura et al. |
6201629 | March 13, 2001 | McClelland et al. |
6204974 | March 20, 2001 | Spitzer |
6222677 | April 24, 2001 | Budd et al. |
6349001 | February 19, 2002 | Spitzer |
6353492 | March 5, 2002 | McClelland et al. |
6353503 | March 5, 2002 | Spitzer et al. |
6356392 | March 12, 2002 | Spitzer |
6384982 | May 7, 2002 | Spitzer |
6538799 | March 25, 2003 | McClelland et al. |
6618099 | September 9, 2003 | Spitzer |
6690516 | February 10, 2004 | Aritake et al. |
6700632 | March 2, 2004 | Taniguchi et al. |
6701038 | March 2, 2004 | Rensing et al. |
6704070 | March 9, 2004 | Taniguchi et al. |
6717635 | April 6, 2004 | Taniguchi et al. |
6724354 | April 20, 2004 | Spitzer et al. |
6738535 | May 18, 2004 | Kanevsky et al. |
6747611 | June 8, 2004 | Budd et al. |
6829095 | December 7, 2004 | Amitai |
6879443 | April 12, 2005 | Spitzer et al. |
7158096 | January 2, 2007 | Spitzer |
7242527 | July 10, 2007 | Spitzer et al. |
7391573 | June 24, 2008 | Amitai |
7457040 | November 25, 2008 | Amitai |
7576916 | August 18, 2009 | Amitai |
7577326 | August 18, 2009 | Amitai |
7643214 | January 5, 2010 | Amitai |
7663805 | February 16, 2010 | Zaloum et al. |
7672055 | March 2, 2010 | Amitai |
7674028 | March 9, 2010 | Cassarly et al. |
7724441 | May 25, 2010 | Amitai |
7724442 | May 25, 2010 | Amitai |
7724443 | May 25, 2010 | Amitai |
7843403 | November 30, 2010 | Spitzer |
7900068 | March 1, 2011 | Weststrate et al. |
8004765 | August 23, 2011 | Amitai |
8059342 | November 15, 2011 | Burke |
8098439 | January 17, 2012 | Amitai et al. |
8189263 | May 29, 2012 | Wang et al. |
20010048548 | December 6, 2001 | Yee |
20020021384 | February 21, 2002 | Taniguchi et al. |
20030080450 | May 1, 2003 | Taniguchi et al. |
20030086031 | May 8, 2003 | Taniguchi et al. |
20030090439 | May 15, 2003 | Spitzer et al. |
20030218718 | November 27, 2003 | Moliton et al. |
20040066817 | April 8, 2004 | Ungar |
20050007672 | January 13, 2005 | Wu |
20050127278 | June 16, 2005 | Cok |
20050174651 | August 11, 2005 | Spitzer et al. |
20050180021 | August 18, 2005 | Travers |
20050213626 | September 29, 2005 | Ungar |
20050219152 | October 6, 2005 | Budd et al. |
20060192306 | August 31, 2006 | Giller et al. |
20060192307 | August 31, 2006 | Giller et al. |
20080062400 | March 13, 2008 | Shioi et al. |
20080198890 | August 21, 2008 | Ungar et al. |
20080219025 | September 11, 2008 | Spitzer et al. |
20090122414 | May 14, 2009 | Amitai |
20100046070 | February 25, 2010 | Mukawa |
20100103078 | April 29, 2010 | Mukawa et al. |
20100149073 | June 17, 2010 | Chaum et al. |
20100157433 | June 24, 2010 | Mukawa et al. |
20100278480 | November 4, 2010 | Vasylyev |
20110043142 | February 24, 2011 | Travis et al. |
20110213664 | September 1, 2011 | Osterhout et al. |
20120301074 | November 29, 2012 | Spitzer |
20130016292 | January 17, 2013 | Miao et al. |
20130033756 | February 7, 2013 | Spitzer et al. |
2 272 980 | June 1994 | GB |
2007-156096 | June 2007 | JP |
2008-122475 | May 2008 | JP |
WO 96/05533 | February 1996 | WO |
- Levola, T., “Diffractive Optics for Virtual Reality Displays”, Academic Dissertation, Joensuu 2005, University of Joensuu, Department of Physics, Vaisala Laboratory, 26 pages.
- Mukawa, H. et al., “8.4: Distinguished Paper: A Full Color Eyewear Display using Holographic Planar Waveguides”, SID Symposium Digest of Technical Papers, 2008, vol. 39, Issue 1, pp. 89-92.
- Lee, Daniel C. et al., “Monolithic Chip-to-chip WDM Optical Proximity Coupler Utilizing Echelle Grating Multiplexer/Demultiplexer Integrated with Micro Mirrors Built on SOI Platform,” Photonics Society Summer Topical Meeting Series, 2010 IEEE, pp. 215-216.
- PCT/US2012/036317, PCT International Search Report and Written Opinion, mailed Oct. 30, 2012, 7 pages.
Type: Grant
Filed: May 27, 2011
Date of Patent: Apr 15, 2014
Patent Publication Number: 20120301074
Assignee: Google Inc. (Mountain View, CA)
Inventor: Mark B. Spitzer (Sharon, MA)
Primary Examiner: Rhonda Peace
Application Number: 13/117,965
International Classification: G02B 6/00 (20060101); G02B 6/34 (20060101); G02B 6/26 (20060101); G02B 6/42 (20060101);